A Development of LVDT Demodulator Circuit Based on FPAA Chip

Abstract

This paper presents a demodulator circuit for LVDT based on the field programmable analog array implemented. The proposed circuit uses the ratio matrix method and employs a single CMOS Field Programmable Analog Array (FPAA) device. It consists of a summing amplifier, divider circuit, and lowpass filter. The demodulator circuit’s functional elements are realized by employing the available Configurable Analogue Modules (CAMs) of the FPAA AN231E04 from AnadigmDesigner®2. Thus, direct current (DC) voltage between -2.43 and +2.3 at 2.5 kHz is proportional to displacement -3 mm until +2.8 mm is outputted. Results show that displacement sensor nonlinear error is γ = 0.27%.